Oral administration of whipworm eggs to healthy adults

A Controlled Human Infection Study of Orally Administered Trichuris Trichiura Eggs in Naïve Adults

This study will try giving small, measured doses of Trichuris trichiura (whipworm) eggs by mouth to healthy adults with no prior exposure to see if infection is safe and can be reliably produced.

Quick facts

• Phase: Phase 1
• Study type: Interventional
• Enrollment: 18 (estimated)
• Ages: 18 Years to 45 Years
• Sex: All
• Sponsor: George Washington University (Academic / other)
• Locations: 2 sites (Washington D.C., District of Columbia and 1 other locations)
• Trial ID: NCT05706116 on ClinicalTrials.gov

What this trial studies

This is an open-label, dose-escalation feasibility study enrolling up to 18 healthy, trichuriasis‑naïve adults at George Washington University and the NIH Clinical Center. Participants will be placed into up to three cohorts and receive a single oral inoculation of 150, 300, or (optional) 450 embryonated Trichuris trichiura eggs on Day 0, with cohorts staggered and safety data reviewed before escalating dose. The study will monitor tolerability, safety, and whether the inoculum leads to detectable infection over a follow-up period of roughly 10 months per participant. Cohort 3 will only proceed if the intermediate dose is well tolerated and does not cause significant adverse events.

Who should consider this trial

Good fit: Ideal candidates are healthy adults aged 18–45 who have no prior trichuriasis exposure, can attend all study visits for the ~10-month follow-up, and agree to study requirements such as contraception if applicable.

Not a fit: People who are pregnant, breastfeeding, immunocompromised, already infected with whipworm, outside the age range, or seeking direct therapeutic benefit are unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, the model could provide a reliable way to study whipworm infection and help speed development of vaccines or treatments.

How similar studies have performed: Controlled human infection models exist for some intestinal parasites (for example, hookworm), but a Trichuris trichiura CHIM is relatively novel and has been only limitedly tested in humans.

Eligibility criteria

Inclusion Criteria:

1. Males or females between 18 and 45 years, inclusive.
2. Good general health as determined by means of the screening procedures.
3. Available for the duration of the trial (approximately 7.5 months).
4. Willingness to participate in the study as evidenced by signing the informed consent document.

Exclusion Criteria:

1. Pregnancy as determined by a positive urine human choriogonadotropin (hCG) (if female).
2. Participant unwilling to use reliable contraception methods while participating in the study (if female of reproductive potential who is engaging in sexual activity that could lead to pregnancy); being of reproductive potential is defined as not being surgically sterile, abstinent from intercourse with a male partner, in a monogamous relationship with a vasectomized partner, at least 2 years post-menopausal, or determined otherwise by medical evaluation to be sterile.
3. Currently lactating and breast-feeding (if female).
4. Evidence of clinically significant neurologic, cardiac, pulmonary, hepatic, rheumatologic, autoimmune, diabetes, or renal disease by history, physical examination, and/or laboratory studies.
5. Has a diagnosis of schizophrenia, bipolar disease or other major psychiatric condition that would make compliance with study visits/procedures difficult (e.g., subject with psychoses or history of suicide attempt or gesture in the 3 years before study entry, ongoing risk for suicide).
6. Known or suspected immunodeficiency or immunosuppression as a result of an underlying illness or treatment.
7. Laboratory evidence of liver disease (alanine aminotransferase \[ALT\] greater than 1.25-times the upper reference limit).
8. Laboratory evidence of renal disease (serum creatinine greater than 1.25-times the upper reference limit).
9. Laboratory evidence of hematologic disease (hemoglobin \<11.1 g/dl \[females\] or \<12.5 g/dl \[males\]; absolute leukocyte count \<3.4 or \>11.0 x 103/mm3; absolute eosinophil count \>0.6 x 103/mm3 or platelet count \<125 x 103/mm3).
10. Positive fecal occult blood test.
11. Infection with a pathogenic intestinal helminth as determined by stool examination for ova and parasites.
12. History of iron deficiency anemia or laboratory evidence of iron deficiency (serum ferritin concentration below the lower reference limit).
13. Other condition that in the opinion of the investigator would jeopardize the safety or rights of a volunteer participating in the trial or would render the participant unable to comply with the protocol.
14. Volunteer has had medical, occupational, or family problems as a result of alcohol or illicit drug use during the past 24 months.
15. Positive ELISA for hepatitis B surface antigen (HBsAg).
16. Positive confirmatory test for HIV infection.
17. Positive confirmatory test for hepatitis C virus (HCV) infection.
18. Using or intends to continue using oral or parenteral corticosteroids, high-dose inhaled corticosteroids (\>800 μg/day of beclomethasone dipropionate or equivalent) or other immunosuppressive or cytotoxic drugs within 30 days of the volunteer's expected enrollment in this study or planned use during the study.
19. Known allergy to albendazole.
20. History of previous infection with T. trichiura or continuous residence for more than 6 months in a T. trichiura-endemic area.

Where this trial is running

Washington D.C., District of Columbia and 1 other locations

• George Washington University Medical Faculty Associates — Washington D.C., District of Columbia, United States (Recruiting)
• NIH Clinical Center — Bethesda, Maryland, United States (Recruiting)

Study contacts

• Study coordinator: David Diemert, MD

Conditions Whipworm; Trichuriasis; Controlled Human Infection